<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>三种布局</title>
    <style type="text/css">
        body,ul{
            margin: 0;
            padding: 0;
        }

        ul {
            list-style: none;
        }

        .container {
            width: 1000px;
            /* height: 1500px;
            border: 2px solid red; */
            margin: 30px auto 0px;
        }
        .column2 {
            /* border: 2px solid black; */
        }
        .column2 .column2-1 {
            width: 700px;
            height: 300px;
            background-color: aquamarine;
            float: left;
        }

        .column2 .column2-2 {
            width: 280px;
            height: 300px;
            background-color: yellow;
            float:right
        }
        .clear {
            clear:both;
        }

        .column3 {
            /* border: 2px solid blue; */
            margin-top: 20px;
        }

        .column3 .column3-1 {
            width: 200px;
            height: 300px;
            background-color: aqua;
            float: left;
        }

        .column3 .column3-2 {
            width: 400px;
            height: 300px;
            background-color: aquamarine;
            float: left;
            margin-left: 20px;
        }

        .column3 .column3-3 {
            width: 360px;
            height: 300px;
            background-color: rgb(40, 80, 66);
            float: right;
        }

        .clearfix::after{
            content:"";
            display: block;
            clear:both;
        }

        .column-n {
            margin-top: 20px;
            /* border: 2px solid blue; */
        }

        .column-n ul {
            /* background-color: aquamarine; */
        }

        .column-n ul li {
            /* border: 1px solid red; */
            width: 190px;
            height: 200px;
            float: left;
            margin: 5px;
            background-color: red;
        }

    </style>
</head>
<body>
    <div class="container">
        <div class="column2"> 
            <div class="column2-1"> </div>
            <div class="column2-2"> </div>
            <div class="clear"></div>
        </div>


        <div class="column3 clearfix">
            <div class="column3-1"> </div>
            <div class="column3-2"> </div> 
            <div class="column3-3"> </div>        
        </div>

        <div class="column-n">
            <ul class="clearfix">
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
                <li></li>
            </ul>
        </div>

    </div>
</body>
</html>